<!DOCTYPE html>
<html>
<body>

<form action="/cgi-bin/calculator.cgi" method="post">
First num:<br>
<input type="text" name="a" value="123">
<br>
Second num:<br>
<input type="text" name="b" value="456">
<br><br>
<input type="submit" value="Submit">
</form> 

</body>
</html>
